In 2011, astronauts Brian Harper, played by Patrick Wilson, and Jocinda Fowler, portrayed by Halle Berry, along with newcomer Marcus, embark on a Space Shuttle mission aimed at repairing a satellite. Their mission takes a catastrophic turn when they are suddenly attacked by a mysterious entity known as the Black Swarm, which results in the death of Marcus and leaves Fowler incapacitated before Harper can safely return to the shuttle. Initially celebrated as a hero for successfully piloting the damaged spacecraft back to Earth despite having no functional onboard electronics, Harper's attempts to share his harrowing story are disregarded by NASA. An extensive investigation spanning eighteen months ultimately places blame on human error, and Harper's truth is met with skepticism. In a pivotal moment, Fowler fails to support him during a crucial hearing, leading to Harper's dismissal from NASA.
As time passes, Harper goes through a painful divorce from his wife Brenda, played by Carolina Bartczak, who receives custody of their son Sonny, portrayed by Charlie Plummer. Brenda remarries Tom, a Lexus dealer, who enjoys considerable wealth. Fast forward ten years, and conspiracy theorist K.C. Houseman, played by John Bradley, who believes the Moon is an artificial mega-structure, utilizes research telescope time to uncover alarming data: the Moon's orbit is inexplicably shifting closer to Earth. However, his attempts to alert NASA fall on deaf ears, prompting him to reach out to Harper, who at first dismisses his claims. Undeterred, Houseman takes to social media to publicize his findings.
NASA eventually confirms the anomaly and initiates a mission to the Moon aboard an SLS Block 2 spacecraft. Unfortunately, the same Swarm returns once again, resulting in the tragic loss of all three lunar astronauts who were sent to investigate a deep artificial shaft that has opened on the Moon's surface. Meanwhile, Sonny finds himself entangled with the law due to a drunk driving arrest, and Harper struggles to free him from jail. Tom, leveraging his wealth and connections, promises to secure Sonny's release by the weekend. It is during this turmoil that Harper realizes Houseman was indeed correct about the looming danger, leading them both to survive a catastrophic tidal surge that devastates the entire west coast of the United States.
As the Moon's orbit deteriorates further, bringing with it disastrous consequences such as tsunamis and atmospheric disturbances, Fowler, now the deputy director of NASA, uncovers startling truths about the Moon's surface abnormalities that were first detected during the historic Apollo 11 mission. She learns from Holdenfield, portrayed by Donald Sutherland, a former NASA official, that a radio blackout during Apollo 11 was orchestrated to conceal unsettling findings that suggested the Moon may indeed be hollow. Accessing the hearing files related to Harper's case, she finds compelling evidence that supports Harper's claims.
In desperation, Fowler retrieves a military program known as ZX7 that developed an EMP device meant to combat the Swarm, which had been discarded due to budget constraints. With urgent determination, Fowler rallies Harper and Houseman for a new mission utilizing the retired Space Shuttle Endeavour. Harper agrees to participate but demands Sonny’s release as a condition. The mission faces challenges, including the loss of an engine mid-flight, leading Fowler to initially disband the crew. However, a last-minute decision prompts Harper, Houseman, and Fowler to launch with the EMP, narrowly evading a colossal tsunami that obliterates the Vandenberg Space Force Base.
As they combat the Swarm, which is drawn to the shuttle's organic presence, Harper ingeniously disables all electronics onboard to evade detection. Upon entering the Moon's interior, they discover that the Swarm is harvesting energy from a white dwarf located at the Moon's core, a fact that disrupts the mega-structure's orbit. They soon learn that this cosmic creation dates back to an ancient civilization that had built the Moon as an ark to preserve humanity from a rogue AI. The Swarm represents this malevolent force, reacting aggressively to organic life.
With the guidance of a benign AI from the Moon's core, Harper formulates a plan to entrap the malicious AI and prepare the EMP for detonation. As the Moon continues its perilous descent towards Earth, the President issues a nuclear strike order to eliminate the Moon, though General Doug Davidson, portrayed by Eme Ikwuakor, bravely defies this order to protect the lives of Fowler, Harper, and Houseman, ultimately sacrificing his own life.
Meanwhile, Sonny's determination to reach safety leads him to escort Fowler's son, Jimmy, alongside their nanny, through the chaos resulting from the Moon's approach. The group, which includes Brenda and her new husband Tom, finds themselves fighting against the elements, facing one disaster after another en route to Davidson's bunker. Tragically, Tom sacrifices himself to save his daughter when the Moon's gravitational pull strips away their atmosphere.
Houseman uses the EMP device from their lunar module to lure the Swarm away from their spacecraft and detonates it, knowing it will cost him his life. His sacrifice enables Fowler and Harper to escape back to an Earth that is now within reach. With the Moon's systems reinstated, the catastrophic damage begins to reverse as it resumes its proper orbit. The pair successfully land in Colorado and reunite with their loved ones, including Sonny, Jimmy, and Brenda.
In a moving twist, the Moon's operating AI reveals it has preserved a copy of Houseman's consciousness, appearing to him as a projection of his mother and his beloved cat, Fuzz Aldrin. The AI informs them that the time has come to commence the vital task of repairing the extensive destruction touched off by the Moon's chaotic descent.
